Duncan, H. (1856). Sacred philosophy of the seasons: Illustrating the perfections of God in the phenomena of the year. Robert Carter & Brothers.
توثيق أسلوب شيكاغو (الطبعة السابعة عشر)Duncan, Henry. Sacred Philosophy of the Seasons: Illustrating the Perfections of God in the Phenomena of the Year. New York: Robert Carter & Brothers, 1856.
توثيق جمعية اللغة المعاصرة MLA (الطبعة الثامنة)Duncan, Henry. Sacred Philosophy of the Seasons: Illustrating the Perfections of God in the Phenomena of the Year. Robert Carter & Brothers, 1856.
تحذير: قد لا تكون هذه الاستشهادات دائما دقيقة بنسبة 100%.